Sgarbossa's criteria

Background

Assesses likelihood that patient with chest pain and baseline LBBB has myocardial damage
- Criteria also applies to LBBB due to ventricularly paced rhythm^[1]
Low sensitivity(20%), high specificity (98%)
- Still consider PCI/t-PA for patients with LBBB and "good story" despite not meeting the criteria

Sgarbossa's Original Criteria

ST elevation ≥1 mm in a lead with upward (concordant) QRS complex - 5 points
ST depression ≥1 mm in lead V1, V2, or V3 - 3 points
ST elevation ≥5 mm in a lead with downward (discordant) QRS complex - 2 points
- Least specific of criteria, see Smith's modification

Smith's Modified Sgarbossa 3rd Rule

Changes the 3rd rule of original Sgarbossa's Criteria to be ST depression OR elevation discordant w/ the QRS complex and w/ a magnitude of at least 25% of the QRS increases Sn from 52% to 91% at the expense of reducing Sp from 98% to 90%^[3]

Sgarbossa original criteria

Discussion with a cardiologist should precede activation of the Cath Lab for any of the Sgarbossa or modified Sgarbossa criteria

↑ Madias JE. The nonspecificity of ST-segment elevation > or =5.0 mm in V1-V3 in the diagnosis of acute myocardial infarction in the presence of ventricular paced rhythm. J Electrocardiol 2004 Apr; 37(2) 135-9.
↑ Sgarbossa E. et al.. "Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block. GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) Investigators". NEJM. 1996. 334(8):481-7
↑ Smith, S. et al. Diagnosis of ST-Elevation Myocardial Infarction in the Presence of Left Bundle Branch Block With the ST-Elevation to S-Wave Ratio in a Modified Sgarbossa Rule. 60(6). 766-776